Rep. Ed Jones, an affable Democrat from Tennessee who has overseen a great blossoming of the Farmers Home Administration lending program over the years, can't quite make up his mind as to whether he'll fight President Reagan's proposed 25 percent cut in his favorite program.

Jones has met with Agriculture Secretary John R. Block five times in the past few days, but says he's still confused about just what the administration wants.

Reagan's budget book outlines cuts in farmers' loans, which Jones, chairman of the Agriculture subcommittee on conservation and credit, said, "I won't stand for." But Block told him what the administration is really targeting -- reductions Jones called "logical."

Rep. William D. Ford (D-Mich.), chairman of the House Post Office and Civil Service Committee, is equally confused. He has not received any specifics on how Reagan wants to slow federal pay raises. "Those who are responding to the cuts are dealing with smoke and mirrors," he said. "We haven't got any figures."

Whatever is proposed by the administration over the next few weeks, Ford and Jones are among more than a dozen Democratic committee and subcommittee chairmen who will have enormous say in whether the Republican program passes Congress.

Even if a budget reconciliation resolution, ordering cuts, is passed by the House, men like Jones and Ford will hold hearings on their areas of jurisdiction and will influence the shape of the resolution.

"The Agriculture Committee is not going to sit down and play dead," Jones said. "We never have and I don't think we will now."

Another Agriculture subcommittee chairman, Fred Richmond (D-N.Y.), who oversees the food stamp program, seemed equally confident that legislative committees could shape the outcome of the economic program. Reagan may want to cut $1.7 billion, or 15 percent of the food stamp program, but Richmond plans to hold a month of hearings to take testimony from poor people, farmers, the beef industry, the diary industry and others who have a stake in the program.

To cut food stamp funds, basic food stamp legislation would have to be altered, Richmond said, even if the administration tries to force such a move through a budget reconciliation measure.

"They don't have the votes," Richmond said. "the bill passed by 80 percent last year. The majority of food stamp recipients are not black and Hispanic. They're rural white women from Mississippi with three children.

"Eighty-five percent of people on food stamps have family incomes under $6,000 a year. If we don't feed these children, they can't learn in school. You can't pare 15 percent out of children's bellies."

Indignation was equally strong from Henry A. Waxman (D-Calif.), who heads the House Commerce subcommittee on health and the environment. Waxman oversees Medicaid.

Under Reagan's proposal. "The first benefits to go would be optional Medicaid benefits like preventive health programs for children, and home health programs which provide alternatives to nursing home care," Waxman said. "Coverage of out-patient services, physician care and medical devices such as wheelchairs would likely be reduced severely.

"It may have been reassuring for some to hear the president state last night that the programs that help the 'disabled, the elderly, all those with true need' are 'exempt from any cuts.' Unfortunately, the president's claim is simply untrue. The needy are, in fact, jeopardized by his budget slashes."

Rep. Robert A. Roe (D-N.J.), one of the fathers of the Economic Development Administration, said he will "fight for its survival. . . . This is the only federal program on line that can provide community aid to areas affected by severe economic impacts. . . . It is a job savings program."

Rep. James J. Howard (D-N.J.), chairman of the House Public Works Committee and a mass transit specialist, said, "Federal operating subsidies [which Reagan wants to cut out] are the lifeblood of many transit systems.The Reagan administration views this as a rich man's subsidy. I am ready to accept cuts in parts of my committee's functions." He added that he would "vigorously defend" mass transit.

Another program the administration wants to cut, the Section 8 housing program for the poor, will also be controversial. Rep. Edward P. Boland (D-Mass.), chairman of the House Appropriations subcommittee that oversees housing, said he was "willing to take a look at it. . . . It is a terribly expensive program," but, "I'm not about to destroy the only housing [assistance] game in town."